Crystal structure and Hirshfeld surface analysis of a copper(II) complex with ethylenediamine and non-coordinated benzoate

In the title compound, diaquabis(ethylenediamine-kappa N-2,N')copper(II) bis(2-nitrobenzoate), [Cu(C2H8N2)(2)(H2O)(2)](C7H4NO4)(2), two diaquabis(ethylenediamine)copper(II) cations and four nitrobenzoate anions are present in the asymmetric unit. All four anions are 'whole-molecule' disordered over two sets of sites. The major components have refined occupancies of 0.572 (13), 0.591 (9), 0.601 (9) and 0.794 (10). The Cu-II ions exhibit slightly distorted octahedral geometries. In the crystal, cations and anions are connected to each other via N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds, forming a two-dimensional network parallel to (200). The intermolecular contacts in the crystal were further analysed using Hirshfeld surface analysis, which indicates that the most significant contacts are O center dot center dot center dot H/H center dot center dot center dot O (42.9%), followed by H center dot center dot center dot H (35.7%), C center dot center dot center dot H/H center dot center dot center dot C (14.2%), C center dot center dot center dot C (2.9%), C center dot center dot center dot O/O center dot center dot center dot C (2.2%), N center dot center dot center dot H/H center dot center dot center dot N (0.9%) and N center dot center dot center dot O/O center dot center dot center dot N (0.3%).